Quantcast
    MAIN INDEX RULES & LEGEND LOG IN  

Slowtwitch Forums: Triathlon Forum:
Vittoria evo CX tubular tyres recommended pressures

 

   


JustJulian

Sep 3, 08 4:41

Post #1 of 14 (5065 views)
Vittoria evo CX tubular tyres recommended pressures Quote | Reply

Guys, I would first say that I have spend the last 30 minutes using the search facility but can't find what I needed.

I recall a thread, in the not too distant past, about tyre pressures with reference to rider weights. My training partner is using the above tubulars at 130psi for racing and can only weigh (that's a subject we can talk about) 90-100 lbs max! I have said that it's a little on the high side and on the rough roads we race on she must be bouncing about like a pea on a drum!

I can't recall which wheels she is racing on this season but know they are deep rim carbon spoked wheels a la 404s or Planet X equivilent.

Can anyone direct me to the right information that I can present to her please?



"How bad can it be?" - SimpleS


IKnowEverything

Sep 3, 08 5:54

Post #2 of 14 (5037 views)
Re: Vittoria evo CX tubular tyres recommended pressures [JulianInEngland] [In reply to] Quote | Reply

Don't know the thread, but at her weight she should be looking at 110-120 max.


JustJulian

Sep 3, 08 7:23

Post #3 of 14 (5004 views)
Re: Vittoria evo CX tubular tyres recommended pressures [IKnowEverything] [In reply to] Quote | Reply

That was the ballpark I was thinking of too, I wanted some stats to back it up. The thread I was thinking of started off with Michelin Pro Race figures but I believe it widened out to other manufacturers too.



"How bad can it be?" - SimpleS


Longboarder

Sep 3, 08 7:35

Post #4 of 14 (4999 views)
Re: Vittoria evo CX tubular tyres recommended pressures [JulianInEngland] [In reply to] Quote | Reply

Julian, I have the same tires. My wt is 141lbs(today). If it's a long race, HIM, I pump them up to 125lbs before I leave the hotel room. FWIW: They seem to run best between 110-120 for me.


Train safe & smart
Bob



JustJulian

Sep 3, 08 7:45

Post #5 of 14 (4988 views)
Re: Vittoria evo CX tubular tyres recommended pressures [Longboarder] [In reply to] Quote | Reply

Thanks, Bob we are getting to the core now. Do you know anyone around the 105lb size that uses them too? She a tiny pocket rocket but stubborn and might not believe what we welterweights use!



"How bad can it be?" - SimpleS


Longboarder

Sep 3, 08 7:56

Post #6 of 14 (4980 views)
Re: Vittoria evo CX tubular tyres recommended pressures [JulianInEngland] [In reply to] Quote | Reply

Yea, I remember the post your talking about but I can't find it. But if I remember she would be at 100psi max. I only go with 125psi due to pressure loss over a long day. But even then it's a rough ride and "maybe" a bit slower.


Train safe & smart
Bob



TriChris14

Sep 3, 08 8:05

Post #7 of 14 (4973 views)
Re: Vittoria evo CX tubular tyres recommended pressures [JulianInEngland] [In reply to] Quote | Reply

I was the guy who asked bout the michelins (cus I am going back to clinchers for racing). I have the vittoria cx tubular now, and I run them b/w 130 and 135. I am however 135 lbs. Although I have run them higher than that before. I would suggest 120. Reason being, if it is a longer race (4-5 hrs of riding) those suckers (as good as they are) lose air. This is because they are a latex inner tube. The other day, I did the 24 hrs of Triathlon, and about every 5 hrs they lost 30 lbs of tires pressure. The upside however is that they are among the fastest rolling resistance tubulars out there.

Chris

Hope this helps.


Tom A.

Sep 3, 08 8:18

Post #8 of 14 (4968 views)
Re: Vittoria evo CX tubular tyres recommended pressures [JulianInEngland] [In reply to] Quote | Reply

In Reply To:
Guys, I would first say that I have spend the last 30 minutes using the search facility but can't find what I needed.

I recall a thread, in the not too distant past, about tyre pressures with reference to rider weights. My training partner is using the above tubulars at 130psi for racing and can only weigh (that's a subject we can talk about) 90-100 lbs max! I have said that it's a little on the high side and on the rough roads we race on she must be bouncing about like a pea on a drum!

I can't recall which wheels she is racing on this season but know they are deep rim carbon spoked wheels a la 404s or Planet X equivilent.

Can anyone direct me to the right information that I can present to her please?

Since the Zipp Tangentes are basically the same tire with a different tread, it should be OK to use the recommendations on the Tangente box:



So...it looks like she should be using more like 110-112 psi, or on rough roads 105-109 on the front and 103-108 on the rear.

In my own testing on the "open tubular" version of these tires (Open Corsa KS) and latex tubes, I found that it was FAR better to "err" on the side of slightly too little pressure, than too much.

http://forum.slowtwitch.com/...%20pressure;#1909561



Now, that data above is for MY WEIGHT (73kg), and MY ROAD...at her significantly lower weight, the "breakpoint" pressure (the pressure above which the total resistance to forward motion rises dramatically) may be at an even LOWER pressure.

Not only is she needlessly bouncing herself around out there running 130psi, but she's also slowing herself down too.

HTH,
Tom



http://bikeblather.blogspot.com/

(This post was edited by Tom A. on Sep 3, 08 8:33)


Tom A.

Sep 3, 08 8:23

Post #9 of 14 (4963 views)
Re: Vittoria evo CX tubular tyres recommended pressures [TriChris14] [In reply to] Quote | Reply

In Reply To:
I was the guy who asked bout the michelins (cus I am going back to clinchers for racing). I have the vittoria cx tubular now, and I run them b/w 130 and 135. I am however 135 lbs. Although I have run them higher than that before. I would suggest 120. Reason being, if it is a longer race (4-5 hrs of riding) those suckers (as good as they are) lose air. This is because they are a latex inner tube. The other day, I did the 24 hrs of Triathlon, and about every 5 hrs they lost 30 lbs of tires pressure. The upside however is that they are among the fastest rolling resistance tubulars out there.

Chris

Hope this helps.

Sounds to me like you might have a leaky valve or stem extender. You should only lose about 1/2 that amount at most in 24 hours total with latex tubes.



http://bikeblather.blogspot.com/


JustJulian

Sep 3, 08 13:21

Post #10 of 14 (4914 views)
Re: Vittoria evo CX tubular tyres recommended pressures [Tom A.] [In reply to] Quote | Reply

Tom/Chris, thank you for your assistance and information that was a great help and exactly what I needed.

Cheers.



"How bad can it be?" - SimpleS


Sasquatch

Sep 3, 08 18:44

Post #11 of 14 (4870 views)
Re: Vittoria evo CX tubular tyres recommended pressures [Tom A.] [In reply to] Quote | Reply

I don't think he does have a leaky stem or extender. I glued up a set last week in preparation for IMWI, Vittoria valve extenders with teflon tape. I weigh 200lbs. I've started my last few rides with 140lbs. in the tires. The following day the tires have been +_ 90 lbs with both tires having lost very similar pressure. Granted, that's closer to 24 hrs than 5, but I'd imagine the rate of loss slows with lower pressure.

With decent weather, I'll ride the course in around 5:15. What pressure to start with in transition at 6:00 a.m., roughly two hours before the ride? Thoughts?


bradl016

Mar 21, 13 13:03

Post #12 of 14 (2142 views)
Re: Vittoria evo CX tubular tyres recommended pressures [Sasquatch] [In reply to] Quote | Reply

Holy necropost, Batman!

I'd just like to point out how helpful Google (and the search function) can be.

Thinking about this weekend - what tire pressure should I run?
*searches*
Finds graph of Ccr with the exact weight and tire I'm using.

Awesome.

So, I'll be running 115 ish in my RR this weekend!

---------------------------------
Tulsa Wheelmen pb Tulsa Tough & ICEdot
Oklahoma Cat 3 TT Champion - 2013
District Bicycles - Stillwater, USA
Joe Martin 2014 Cat 3 GC


nickag

Mar 21, 13 13:20

Post #13 of 14 (2125 views)
Re: Vittoria evo CX tubular tyres recommended pressures [bradl016] [In reply to] Quote | Reply

http://www.vittoria.com/...recom-tyre-pressure/


Dave_Ryan

Mar 21, 13 13:41

Post #14 of 14 (2107 views)
Re: Vittoria evo CX tubular tyres recommended pressures [nickag] [In reply to] Quote | Reply

nickag wrote:
http://www.vittoria.com/tech/recom-tyre-pressure/

Cute calculator but it ignores both tire size and clincher rim size both of which influence ideal tire pressure. For instance a Corsa CX on a 19mm rim in the 21c size should be run at a substantially higher pressure for the same conditions and rider weight as the 25c version of the same tire on a wide clincher rim.

If you go with HED's recommendations you'd drop at least 11% for the same tire when mounted on one of their wider C2 rims and larger tires (e.g. 25c vs. 23c) also roll and run best at slightly lower pressure.

   
 
 
 



Your Racing Helmet
What helmet brand do you anticipate most often using while racing in triathlons?
Giro
Rudy Project
Specialized
Louis Garneau
Lazer
Bell
Kask
Casco
Other